Your concerns about SimpleFX are not a surprise because other guys have raised the same concerns now and again. While SimpleFX offers high leverage up to 1:500 and has a user-friendly platform, it is not regulated by major financial authorities. This lack of regulation can indeed raise concerns about the security of your funds.
For alternatives, you can use:
Pepperstone: This broker is regulated by multiple authorities, including the FCA (UK) and ASIC (Australia). They offer leverage up to 1:500 for non-EU clients.
FXTM (ForexTime): Regulated by CySEC and the FCA, FXTM offers leverage up to 1:2000 for non-EU clients.
SimpleFX prioritizes security with features like segregated accounts and two-factor authentication. While currently unregulated, they’re working on obtaining a license and maintain high security standards to protect client funds.